diff options
Diffstat (limited to 'include/net/checksum.h')
| -rw-r--r-- | include/net/checksum.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/net/checksum.h b/include/net/checksum.h index 7de1acb79a..dd8b4f6dc2 100644 --- a/include/net/checksum.h +++ b/include/net/checksum.h @@ -18,6 +18,7 @@ #ifndef QEMU_NET_CHECKSUM_H #define QEMU_NET_CHECKSUM_H +#include "qemu/bswap.h" struct iovec; uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq); @@ -50,4 +51,48 @@ uint32_t net_checksum_add_iov(const struct iovec *iov, const unsigned int iov_cnt, uint32_t iov_off, uint32_t size); +typedef struct toeplitz_key_st { + uint32_t leftmost_32_bits; + uint8_t *next_byte; +} net_toeplitz_key; + +static inline +void net_toeplitz_key_init(net_toeplitz_key *key, uint8_t *key_bytes) +{ + key->leftmost_32_bits = be32_to_cpu(*(uint32_t *)key_bytes); + key->next_byte = key_bytes + sizeof(uint32_t); +} + +static inline +void net_toeplitz_add(uint32_t *result, + uint8_t *input, + uint32_t len, + net_toeplitz_key *key) +{ + register uint32_t accumulator = *result; + register uint32_t leftmost_32_bits = key->leftmost_32_bits; + register uint32_t byte; + + for (byte = 0; byte < len; byte++) { + register uint8_t input_byte = input[byte]; + register uint8_t key_byte = *(key->next_byte++); + register uint8_t bit; + + for (bit = 0; bit < 8; bit++) { + if (input_byte & (1 << 7)) { + accumulator ^= leftmost_32_bits; + } + + leftmost_32_bits = + (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7); + + input_byte <<= 1; + key_byte <<= 1; + } + } + + key->leftmost_32_bits = leftmost_32_bits; + *result = accumulator; +} + #endif /* QEMU_NET_CHECKSUM_H */ |